While most vehicles, especially automobiles, have carpeted floors, various commercial, agricultural, construction and sports and recreational vehicles have non-carpeted floors to facilitate easy cleaning and to resist soiling.
Until relatively recently, vulcanized rubber sheet material was commonly used as floor coverings for vehicles. Vulcanized rubber can be formed into sheet materials that are relatively inexpensive, and which exhibit low gloss and good tactility for vehicle floor covering applications. However, vulcanized rubber is not recyclable. Spent vulcanized rubber components generally must be disposed of in a landfill. It is of course more desirable to use materials that can be easily recycled, i.e. processed for use in another application. Another problem with vulcanized rubber floor coverings is that they are usually relatively thick and heavy, and therefore have an undesirable effect on vehicle fuel economy.
A relatively inexpensive alternative to vulcanized rubber is polyvinyl chloride floor coverings. Polyvinyl chloride (PVC) can be more easily recycled than vulcanized rubber. However, like vulcanized rubber, polyvinyl chloride floor coverings are generally relatively heavy, and therefore, have an undesirable effect on fuel economy. Generally, PVC also exhibits undesirable glossiness and poor tactility. Another disadvantage is that polyvinyl chloride must generally contain relatively high amounts of plasticizing agents in order to exhibit a desired flexibility for use as a floor covering material. Plasticizing agents tend to diffuse out of the polyvinyl chloride sheet material, volatilize and enter into the environment. The introduction of these plasticizing agents into the environment is highly undesirable.
An alternative to vulcanized rubber and polyvinyl chloride sheet materials for automotive flooring applications is thermoplastic olefin based materials. A problem with thermoplastic olefin based sheet materials is that they typically have a relatively glossy surface and poor tactility, rather than having a relatively high-friction surface as is commonly associated with rubber type materials. Thermoplastic olefins have a relatively smooth, glossy surface and plastic-like feel that is undesirable for floor covering applications.
Ethylene-vinyl acetate (EVA) laminates have also been used as vehicle floor covering materials. However, like the thermoplastic olefin based materials, the ethylene-vinyl acetate materials also exhibit high gloss and poor tactility. Further, the ethylene-vinyl acetate materials also exhibit poor grain retention (i.e., an embossed grain pattern provided to reduce gloss and improve tactility is partially or completely destroyed during normal use of a floor covering when subjected to temperatures frequently achieved during summer).
Conventional techniques used for reducing gloss in polymeric sheet materials, such as thermoplastic olefin based materials and ethylene-vinyl acetate materials have not been particularly effective. For example, while fillers have been successfully used to reduce gloss and improve tactility, the resulting filled material tends to exhibit poor abrasion resistance. Embossed grain patterns which may be created during an extrusion and/or calendering process, reduce glossiness of thermoplastic olefin based materials and ethylene-vinyl acetate materials. However, the surface finishes are lost or at least diminished during thermoforming processes which are required in order to conform the floor covering sheet material to the contours of a vehicle floor.
Accordingly, there remains a need for recyclable, environmentally friendly, sheet materials for vehicle floor covering applications, with good tactility similar to vulcanized rubber materials, good abrasion resistance, grain retention, and heat and ultraviolet light stability.